Current understanding of the effectiveness of the drugs derived from plants belonging to Aconitum, Delphinium and Consolida species (Ranunculaceae) is incomplete and further investigations are desirable. Extracts of more than 50 species of plants of these genera are used for their analgesic, antirheumatic and cardiotonic properties in the Chinese and Indian systems of medicine. The objectives of this research proposal are: (1) To isolate and purify the alkaloids to be tested. (2) to modify structures of active alkaloids for enhancement of antihypertensive activity. (3) to study the mechanism of reflex reception action. (4) to study the actions of alkaloids on autonomic reflexes. Isolation of key alkaloids in adequate amounts will be undertaken so that a pharmacological investigation of these compounds can be pursued. The purified naturally-occurring alkaloids and their derivatives will be screened for CVS activities. Alkaloids that manifest promising hypotensive activity will be structurally modified to enhance maximal therapeutic effects and minimal toxicity.